Hissatsu Chikan Nin 2
Based on the game by Anim.
On her morning commute, a young woman witnesses a guy molesting a woman on the train. Though she does not try to stop him or call for help, she does do something about it: she pleasures herself. She soon gets caught up in the pervert’s world, becoming a willing victim and a recruiter for his dirty games. She then ups the ante, luring her hot friends into the trap. All aboard!